Manage your subscription

Oxygen hitch on space station

The crew of the International Space Station is once again struggling to repair its increasingly troublesome oxygen generator. While a new system is planned, it may not be ready for years.

The Russian-built Elektron unit produces oxygen by splitting water from the station’s drinking supply, a design Russia has used for over a decade. But the unit on the station has become unreliable and last week broke down altogether. Gennady Padalka, the Russian commander of the station, made three attempts to restart the unit without success.

Although the station’s oxygen pressure dropped after the system stopped working, NASA says the …